Wi-Fi Peer-to-Peer (P2P), also known as Wi-Fi Direct, is a recently released specification for device-to-device communication. In the rest of the text, Wi-Fi P2P and Wi-Fi Direct have been used synonymously and interchangeably. The standard builds on the foundation of its predecessor Wi-Fi which is based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, but strikingly differs from it in terms of the need of an Access Point (AP). Bringing down the AP functionality to software, the standard not only does away with the requirement of a specialized hardware for playing the role of AP, but also offers a fast and secure mode of ad-hoc communication. Thus, several Wi-Fi P2P capable devices can form a group and exchange information among each other without requiring any AP or Internet connection.
According to the Wi-Fi Peer-To-Peer (P2P) Technical specification Version 1.4 (NPL 1), Wi-Fi P2P requires one of the devices to act as Group Owner (GO) whose role is analogous to AP in Wi-Fi Infrastructure mode. Any Wi-Fi P2P device is capable of playing the role of GO. Wi-Fi P2P devices interested in sharing information with each other initially engage in a comprehensive process of group formation by which one device is selected as GO. All devices stay associated to the GO and communication can only be performed inside the group.